Y khoa - Dược - Chapter 29: The respiratory system

29The Respiratory SystemLearning Outcomes (cont.)29.1 Describe the structure and function of each organ in the respiratory system. 29.2 Describe the events involved in the inspiration and expiration of air. 29.3 Explain how oxygen and carbon dioxide are transported in the blood.Learning Outcomes (cont.)29.4 Compare various respiratory volumes and tell how they are used to diagnose respiratory problems.29.5 Describe the causes, signs and symptoms, and treatments of various diseases and disorders of the respiratory system.IntroductionFunction Move air in and out of lungs Delivers oxygen (O2) Removes carbon dioxide (CO2) External respiration – in the lungsInternal respiration – within the hemoglobinO2O2O2CO2CO2CO2LungsOrgans of the Respiratory System Nose Pharynx Larynx Trachea Bronchial tree LungsOrgans of the Respiratory System (cont.)Nasal CavityNasal septum Nasal conchae Mucous membrane warms and moistens the airCilia eliminate particlesTo DiagramOrgans of the Respiratory System (cont.)Paranasal SinusesAir-filled spaces within the skull bonesReduce the weight of the skull Equalize pressureGive the voice its toneOrgans of the Respiratory System (cont.)Pharynx Larynx Moves air in and out of the trachea Produces sounds of the voiceCartilage and muscleEpiglottisReparatory systemLayrnxOrgans of the Respiratory System (cont.)BackOrgans of the Respiratory System (cont.)BackOrgans of the Respiratory System (cont.)TracheaTubular organ made of rings of cartilage and smooth muscleExtends from the larynx to the bronchiLined with cells possessing ciliaTo DiagramOrgans of the Respiratory System (cont.)Vocal cordsBetween the thyroid cartilage and the cricoid cartilageGlottis~ the opening between the vocal cordsUpper ~ false cords Lower ~ true vocal cordsOrgans of the Respiratory System (cont.)Bronchial tree – branches off the tracheaBronchi Primary or main stemSecondaryTertiary Bronchioles ~ branch off tertiary bronchiTo DiagramOrgans of the Respiratory System (cont.)AlveoliThin sacs of cells surrounded by capillaries“Working tissue”Cellular respiration Carbon dioxide released into alveoliOxygen released into the bloodTo DiagramOrgans of the Respiratory System (cont.)BackAlovelar SacThe lungs contain connective tissue, the bronchial tree, nerves, lymphatic vessels, and blood vessels.LungsCone-shaped organsRight lung – three lobes Left lung – two lobesTo DiagramLungsPleura Membranes surrounding the lungsParietal pleuraVisceral pleuraPleural fluidSurfactant – keeps alveoli from collapsingApply Your KnowledgeTrue or False The nasal conchae supports the mucus membrane and  increases the surface area in the nasal cavity. The larynx functions for both the respiratory and  digestive systems Lower vocal cords produce sound and are the true vocal  cords. Surfactant keeps the alveoli from collapsing between  inspirations. The bronchioles are the “working tissue” of the lungsSUPER!ANSWER:TTTFFpharynxalveoliThe Mechanisms of Breathing The diaphragm contracts and flattens The intercostal muscles raise the ribs Air rich in O2 enters the lungs Breathing Diagram InspirationThe Mechanisms of BreathingBreathing, or pulmonary ventilation, consists of inspiration and expiration. The diaphragm relaxes The intercostal muscles lower the ribs Air rich in CO2 exits the lungsBreathing Diagram ExpirationThe Mechanisms of Breathing (cont.)BackINSPIRIATIONEXPIRATIONThe Mechanisms of Breathing (cont.)Respiratory center of the brainMedulla oblongata ~ rhythm and depth of breathingPons ~ rate of breathingOther factorsCO2 levels in the bloodpH of the bloodFear and painInflation reflexThe Mechanisms of Breathing (cont.)Causes of altered breathing patternsCoughingSneezingLaughingCryingHiccupsYawningSpeaking Apply Your KnowledgeIndicated whether each statement refers to (I) inhalation or (E) exhalation:__ The intercostal muscles lower the ribs__ The diaphragm contracts or flattens__ The intercostal muscles raise the ribs__ The diaphragm relaxes__ Air rich in O2 enters the lungs from the atmosphere__ Air rich in CO2 exits the lungs ANSWER:EEEIIIBRAVO!The Transport of Oxygen and Carbon Dioxide in the BloodOxygenOxygen binds to hemoglobin – oxyhemoglobin Bright red in colorSmall amount oxygen remains dissolved in plasmaThe Transport of Oxygen and Carbon Dioxide in the Blood (cont.)Carbon DioxideBinds to hemoglobin ~ carboxyhemoglobin Most carbon dioxide goes into the plasmaRBCs convert it to carbonic acid used to regulate the pH of the bloodApply Your KnowledgeDescribe what happens to carbon dioxide in the blood.ANSWER: Carbon dioxide can combine with hemoglobin and form carboxyhemoglobin. Most is converted to carbonic acid by RBCs.Super!Respiratory VolumesDifferent volumes of air move in and out of lungs with different intensities of breathingMeasured to assess health of respiratory systemRespiratory Volumes (cont.)Amount of air that moves in or out of the lungs during a normal breathAmount of air that can be forcefully inhaled following a normal inhalationAmount of air that can be forcefully exhaled following a normal exhalation Tidal VolumeInspiratoryReserve VolumeExpiratoryReserve VolumeRespiratory Volumes (cont.)Amount of air that can be forcefully exhaled after the deepest inhalation possibleVolume of air that always remains in the lungs even after a forceful exhalationThe total amount of air the lungs can holdResidual VolumeTotal LungCapacityVital CapacityApply Your Knowledge___ Amount of air that moves during  a normal breath.___ Amount of air that always  remains in the lungs.___ Total amount of air the lungs  can hold.___ Amount of air forcefully exhaled  after deepest inhalation  possible.A. Total lung capacityB. Residual volumeC. Tidal volumeD. Vital capacityMatch the following: ANSWER:CABDGood Job!Common Diseases and Disorders of the Respiratory SystemSnoringDue to vibration of soft tissues when muscles of the palate, tongue, and throat relaxAffects approximately 50% of men and 25% of women over the age of 40Causes daytime sleepinessSeverity of snoringCommon Diseases and Disorders (cont.) DiseaseDescriptionAllergic rhinitisHypersensitivity reaction to various airborne allergens Asthma A condition in which the tubes of the bronchial tree become obstructed due to inflammationAtelectasisCollapsed lung; one symptom is dyspneaCommon Diseases and Disorders (cont.)DiseaseDescriptionBronchitisInflammation of the bronchi often follows a cold; one type of COPD Chronic obstructive pulmonary disease (COPD)A group of lung disorders that limit airflow to lungs and usually cause enlargement of the alveoliEmphysemaA chronic condition associated with smoking that damages the alveoli; one type of COPDCommon Diseases and Disorders (cont.)DiseaseDescriptionInfluenzaA viral disease that attacks the respiratory system; commonly called the flu LaryngitisAn acute inflammation of the larynx causing hoarseness (dysphonia)Legionnaire’s diseaseAcute bacterial pneumonia caused by Legionnaire bacteria that usually grows in the standing water of air conditioning systems Common Diseases and Disorders (cont.) DiseaseDescriptionLung cancerCancer closely associated with smoking and exposure to second-hand smoke; four types of lung cancersPleural effusionA buildup of fluid in the pleural cavityPleuritis / PleurisyInflammation of the membranes that cover the lungs, known as pleuraCommon Diseases and Disorders (cont.) DiseaseDescriptionPneumoconiosisLung diseases that result from years environmental or occupational exposure to different types of dustPneumonia/ PneumonitisAn inflammation of the lungs that is most often caused by a bacterial, viral, or fungal infectionPneumothoraxA collection of air in the chest around the lungs, which may cause atelectasis Common Diseases and Disorders (cont.) DiseaseDescriptionPulmonary edemaA condition in which fluids fill spaces within the lungs, making it very difficult for the lungs to oxygenate the blood Pulmonary embolism A blood clot (embolism) that travels usually from the legs and blocks an artery in the lungsCommon Diseases and Disorders (cont.)DiseaseDescriptionRespiratory distress syndrome (RDS)Syndrome in which a lack of surfactant in the lungs allows the alveoli to collapse on exhalation, resulting in poor oxygenationSevere acute respiratory syndrome (SARS) A viral respiratory disease that is very contagious and sometimes fatalCommon Diseases and Disorders (cont.)DiseaseDescriptionSinusitisAn inflammation of the membranes lining the sinuses of the skull Sudden infant death syndrome (SIDS) A syndrome without characteristic signs or symptoms; usually a baby with this disorder simply goes to sleep and never wakes upCommon Diseases and Disorders (cont.)DiseaseDescriptionTuberculosisPrimarily a respiratory disease caused by various strains of the bacterium Mycobacterium tuberculosis Upper respiratory (tract) infection (URI)Coryza, or the common coldApply Your KnowledgeMatching: Syndrome caused by a lack of  surfactant. Obstruction of bronchial tree due to  inflammation. May cause daytime sleepiness. Coryza A collection of air in the chest. Disorders that limit airflow to the lungs. An accumulation of fluid in the pleural cavity.SnoringAsthmaCOPDPneumothoraxPleural effusionRDSURIANSWER:Correct!FBAGDCEIn Summary29.1 The function of the respiratory system is to move air in and out of the lungs in a process known as ventilation, respiration, or breathing. The larynx contains the vocal cords, which stretch between the thyroid and cricoid cartilages. The lungs contain connective tissue, the bronchial tree, nerves, lymphatic vessels, and blood vessels. The bronchial tree consists of the primary, secondary, and tertiary branches of the bronchi, the bronchioles, and the alveoli.In Summary (cont.)29.2 During inspiration, the diaphragm contracts and the intercostal muscles raise the ribs, increasing the space in the thoracic cavity. This decreases the pressure within the cavity so that the air outside the body passively flows into the thoracic cavity. During expiration, the diaphragm relaxes, pushing up into the thoracic cavity, and the intercostal muscles lower the ribs, forcing the air to flow out of the body. Breathing is controlled by the respiratory center of the brain, located in the pons and medulla oblongataIn Summary (cont.)29.3 Most of the oxygen in the bloodstream binds to the hemoglobin within red blood cells, resulting in oxyhemoglobin, although a small amount does not bind to hemoglobin and remains dissolved in the plasma. Carbon dioxide binds to hemoglobin, resulting in carboxyhemoglobin. Most of the carbon dioxide that enters the blood reacts with water in plasma and cerebrospinal fluid to form carbonic acid. As carbonic acid ionizes, it releases hydrogen and bicarbonate ions, which attach to hemoglobin making its way back to the lungs to be exhaled. In Summary (cont.)29.4 Respiratory volumes are measured to check the health of the respiratory system. The volumes are: tidal volume, inspiratory and expiratory reserve volumes, residual volume, inspiratory capacity, functional residual capacity, vital capacity, and total lung capacity. The normal capacities are found in the chapterIn Summary (cont.)29.5 The diseases and disorders of the respiratory system are many and varied, as are the causes and treatments of these diseases. Many of the more common respiratory disorders with their individual causes and treatments are discussed in detail in the pathophysiology section of this chapter.End of Chapter 29The air of ideas is the only air worth breathing.~Edith Wharton